package com.hdu.hot100.list;

import java.util.List;

public class lc141 {

    class ListNode {
        int val;
        ListNode next;

        ListNode(int x) {
            val = x;
            next = null;
        }
    }

    public class Solution {
        public boolean hasCycle(ListNode head) {

            ListNode slow = head;
            ListNode fast = head;
            while (fast != null && fast.next != null)
            {
                slow = slow.next;
                fast = fast.next.next;
                if (slow == fast)
                {
                    return true;
                }
            }
            return false;
        }
    }
}
